The present invention relates to mixing devices and more particularly to an improved apparatus for gently agitating the contents of a plurality of closed cylindrical containers by simultaneously rotating and rocking the containers.
In the working environment of the scientific laboratory, researchers and technicians utilize a variety of devices to mix or blend the contents of test tubes and vials prior to conducting tests or experiments. Particularly in the field of hematology, such mixing devices are employed to blend blood samples in sealed containers to assure their homogeneity before a pathological or other medical examination. One such type of hematological mixing device involves the impartation of a gentle rocking or see-saw motion to the sealed containers while they are slowly rotated so that the samples are thoroughly mixed without frothing or breakdown of the blood cells. This type of device generally includes a plurality of cylindrical rollers mounted alongside each other having parallel cylindrical axes and positively interengaged to rotate in the same direction and at the same speed on rotational axes that are parallel to each other and angularly disposed to the respectively cylindrical axes so that the rollers rotate in an eccentric fashion.
While existing mixing devices of this type have been successful in properly agitating the contents of sealed cylindrical containers for laboratory tests and experimentation, such devices have experienced problems in the rotational driving and synchronous coupling of the rollers. Gear trains have been employed in such mixing devices to drive and couple the rollers, but have required precision alignments in their mounting to avoid binding and jamming during operation. Furthermore, such alignments have been time-consuming and resulted in costlier assemblies.